--- Car-Selling 
-- A car selling system
-- Powered by lua and moonscript
-- Author: Xing Wenju

-- 1. Model
--@module Car
--@new   The constructor
--@choose    Customer choose specifications
--@produce   show customer specifications
--
--@module    Inventory
--@new    Constructor
--@add_item_by_name   Adding new item name is index value increase
--@add_item_by_index  Adding new item auto index value is a table
